In this paper the loading problem of circular manhole cover for chosen type of material is analyzed. Using the software package Autodesk Simulation Mechanical in educational
version three-dimensional linear static analysis of bending casted circular manhole cover
using the finite element method was conducted. The analysis in several versions of the
different cover construction was conducted. As the circular cover with circular and radial ribs
is circularly symmetrical, in the analysis geometry of only one part of cover has been used.
Firstly, that part of the cover using the finite elements was discretized and then the boundary
conditions of specified load, reliance and boundary conditions of circular symmetry had set.
As analytical solutions are limited to simple geometric problems such as bending of thin
circular plate, in a first place a numerical simulation of a thin circular plate was carried out.
Results of deflection, radial and circular stresses obtained by numerical simulation with
analytical solution are compared. In numerical simulation equivalent stresses with energy
theory of strength (HMH - von Mises) were monitored. After verification of numerical results
of bending thin circular plate, on the bottom of plate the circular ribs were added and
numerical simulation of bending this design of plate was carried out. With notification of
existence of quite a large equivalent stress in one part of plate, another numerical simulation
with addition of radial ribs was carried out. Analyzing the results it was concluded that with
addition of circular and radial ribs at the bottom of cover maximum equivalent stress with the
circular cover passes to the ribs. By analyzing the results of the last simulation material
(ductile or grey iron) selection with respect to a given load was made.